batteries

Alternating and Direct
We're all advised to change the batteries in our smoke detectors once each year. This is truly good and affordable advice, and most of us are happy to comply. If you were to decide on a whim to replace all of the batteries in all of your battery-powered appliances or other devices that incorporate battery backup in their design on that mandated day, however, you might find the number of replacements surprising, the day a long one and the
Easier by Analogy
Several years ago, I was asked to conduct a seminar on basic electricity for the members of a small homeowners' association.  They were working their way alphabetically through the various trade disciplines with which a homeowner might come in contact.  As I recall, they had covered attic fans, brickwork, cabinetry, carpeting, decks and doors at previous meetings.  I learned that I was to be followed in coming months by fences, fireplaces and